红黑树2

rbtree.c

#include
#include
#include
#include "rbtree.h"
static void __rb_rotate_left(struct rb_node *node, struct rb_root *root)
{
        struct rb_node *right = node->rb_right;
        struct rb_node *parent = rb_parent(node);
        if ((node->rb_right = right->rb_left))
                rb_set_parent(right->rb_left, node);
        right->rb_left = node;
        rb_set_parent(right, parent);
        if (parent) {
                if (node == parent->rb_left)
                        parent->rb_left = right;
                else
                        parent->rb_right = right;
        } else
                root->rb_node = right;
        rb_set_parent(node, right);
}
static void __rb_rotate_right(struct rb_node *node, struct rb_root *root)
{
        struct rb_node *left = node->rb_left;
        struct rb_node *parent = rb_parent(node);
        if ((node->rb_left = left->rb_right))
                rb_set_parent(left->rb_right, node);
        left->rb_right = node;
        rb_set_parent(left, parent);
        if (parent) {
                if (node == parent->rb_right)
                        parent->rb_right = left;
                else
                        parent->rb_left = left;
        } else
                root->rb_node = left;
        rb_set_parent(node, left);
}
void rb_insert_color(struct rb_node *node, struct rb_root *root)
{
    struct rb_node *parent, *gparent;
    while ((parent = rb_parent(node)) && rb_is_red(parent)) {
        gparent = rb_parent(parent);
        if (parent == gparent->rb_left)  { // node is left child of parent
            {
                struct rb_node *uncle = gparent->rb_right;
                if (uncle && rb_is_red(uncle)) { // case 1
                    rb_set_black(uncle);
                    rb_set_black(parent);
                    rb_set_red(gparent);
                    node = gparent;
                    continue;
                }
            }
            if (parent->rb_right == node) { // case 2
                struct rb_node *tmp;
                __rb_rotate_left(parent, root);
                tmp = parent;
                parent = node;
                node = tmp;
            }
            // case 3
            rb_set_black(parent);
            rb_set_red(gparent);
            __rb_rotate_right(gparent, root);
        } else { // node is right child of parent
            {
                struct rb_node *uncle = gparent->rb_left;
                if (uncle && rb_is_red(uncle)) { // case 1
                    rb_set_black(uncle);
                    rb_set_black(parent);
                    rb_set_red(gparent);
                    node = gparent;
                    continue;
                }
            }
            if (parent->rb_left == node) { // case 2
                struct rb_node *tmp;
                __rb_rotate_right(parent, root);
                tmp = parent;
                parent = node;
                node = tmp;
            }
            // case 3
            rb_set_black(parent);
            rb_set_red(gparent);
            __rb_rotate_left(gparent, root);
        }
    }
    rb_set_black(root->rb_node);
}
static int rb_compare(struct rb_key key1, struct rb_key key2)
{
    return (key1.key - key2.key);
}
struct rb_node* rb_newnode(struct rb_key *rb_key)
{
    struct rb_node *node = (struct rb_node *)malloc(sizeof(struct rb_node));
    if (node) {
        node->rb_parent = NULL;
        node->rb_left = NULL;
        node->rb_right = NULL;
        node->rb_color = RB_RED;
        memcpy(&node->rb_key, rb_key, sizeof(struct rb_key));
    }
    return node;
}
void rb_insert(struct rb_node *node, struct rb_root *root)
{
    struct rb_node *p = root->rb_node;
    struct rb_node *q = NULL;
    while (p != NULL) {
        q = p;
        if (rb_compare(node->rb_key, p->rb_key) < 0)
            p = p->rb_left;
        else
            p = p->rb_right;
    }
    node->rb_parent = q;
    if (q == NULL) {
        root->rb_node = node;
    } else {
        if (rb_compare(node->rb_key, q->rb_key) < 0)
            q->rb_left = node;
        else
            q->rb_right = node;
    }
    rb_insert_color(node, root);
}
static void __rb_erase_color(struct rb_node *node, struct rb_node *parent, struct rb_root *root)
{
    struct rb_node *other;
    while ((!node || rb_is_black(node)) && node != root->rb_node)
    {
        if (parent->rb_left == node)
        {
            other = parent->rb_right;
            // case 1
            if (rb_is_red(other))
            {
                rb_set_black(other);
                rb_set_red(parent);
                __rb_rotate_left(parent, root);
                other = parent->rb_right;
            }
            // case 2
            if ((!other->rb_left || rb_is_black(other->rb_left)) &&
                (!other->rb_right || rb_is_black(other->rb_right)))
            {
                rb_set_red(other);
                node = parent;
                parent = rb_parent(node);
            }
            else
            {
                // case 3
                if (!other->rb_right || rb_is_black(other->rb_right))
                {
                    struct rb_node *o_left;
                    if ((o_left = other->rb_left))
                        rb_set_black(o_left);
                    rb_set_red(other);
                    __rb_rotate_right(other, root);
                    other = parent->rb_right;
                }
                // case 4
                rb_set_color(other, rb_color(parent));
                rb_set_black(parent);
                if (other->rb_right)
                    rb_set_black(other->rb_right);
                __rb_rotate_left(parent, root);
                node = root->rb_node;
                break;
            }
        }
        else
        {
            other = parent->rb_left;
            // case 1
            if (rb_is_red(other))
            {
                rb_set_black(other);
                rb_set_red(parent);
                __rb_rotate_right(parent, root);
                other = parent->rb_left;
            }
            // case 2
            if ((!other->rb_left || rb_is_black(other->rb_left)) &&
                (!other->rb_right || rb_is_black(other->rb_right)))
            {
                rb_set_red(other);
                node = parent;
                parent = rb_parent(node);
            }
            else
            {
                // case 3
                if (!other->rb_left || rb_is_black(other->rb_left))
                {
                    register struct rb_node *o_right;
                    if ((o_right = other->rb_right))
                        rb_set_black(o_right);
                    rb_set_red(other);
                    __rb_rotate_left(other, root);
                    other = parent->rb_left;
                }
                // case 4
                rb_set_color(other, rb_color(parent));
                rb_set_black(parent);
                if (other->rb_left)
                    rb_set_black(other->rb_left);
                __rb_rotate_right(parent, root);
                node = root->rb_node;
                break;
            }
        }
    }
    if (node)
        rb_set_black(node);
}
void rb_erase(struct rb_node *node, struct rb_root *root)
{
    struct rb_node *child, *parent;
    int color;
    if (!node->rb_left)
        child = node->rb_right;
    else if (!node->rb_right)
        child = node->rb_left;
    else
    {
        struct rb_node *old = node, *left;
        node = node->rb_right;
        while ((left = node->rb_left) != NULL)
            node = left;
        child = node->rb_right;
        parent = rb_parent(node);
        color = rb_color(node);
        if (child)
            rb_set_parent(child, parent);
        if (parent == old) {
            parent->rb_right = child;
            parent = node;
        } else
            parent->rb_left = child;
        node->rb_color = old->rb_color;
        node->rb_parent = old->rb_parent;
        node->rb_right = old->rb_right;
        node->rb_left = old->rb_left;
        if (rb_parent(old))
        {
            if (rb_parent(old)->rb_left == old)
                rb_parent(old)->rb_left = node;
            else
                rb_parent(old)->rb_right = node;
        } else
            root->rb_node = node;
        rb_set_parent(old->rb_left, node);
        if (old->rb_right)
            rb_set_parent(old->rb_right, node);
        goto color;
    }
    parent = rb_parent(node);
    color = rb_color(node);
    if (child)
        rb_set_parent(child, parent);
    if (parent)
    {
        if (parent->rb_left == node)
            parent->rb_left = child;
        else
            parent->rb_right = child;
    }
    else
        root->rb_node = child;
 color:
    if (color == RB_BLACK)
        __rb_erase_color(child, parent, root);
}
struct rb_node *rb_first(struct rb_root *root)
{
    struct rb_node  *n;
    n = root->rb_node;
    if (!n)
        return NULL;
    while (n->rb_left)
        n = n->rb_left;
    return n;
}
struct rb_node *rb_last(struct rb_root *root)
{
    struct rb_node  *n;
    n = root->rb_node;
    if (!n)
        return NULL;
    while (n->rb_right)
        n = n->rb_right;
    return n;
}
struct rb_node *rb_next(struct rb_node *node)
{
    struct rb_node *parent;
    if (rb_parent(node) == node)
        return NULL;
    /* If we have a right-hand child, go down and then left as far
       as we can. */
    if (node->rb_right) {
        node = node->rb_right;
        while (node->rb_left)
            node=node->rb_left;
        return node;
    }
    /* No right-hand children.  Everything down and left is
       smaller than us, so any 'next' node must be in the general
       direction of our parent. Go up the tree; any time the
       ancestor is a right-hand child of its parent, keep going
       up. First time it's a left-hand child of its parent, said
       parent is our 'next' node. */
    while ((parent = rb_parent(node)) && node == parent->rb_right)
        node = parent;
    return parent;
}
struct rb_node *rb_prev(struct rb_node *node)
{
    struct rb_node *parent;
    if (rb_parent(node) == node)
        return NULL;
    /* If we have a left-hand child, go down and then right as far
       as we can. */
    if (node->rb_left) {
        node = node->rb_left;
        while (node->rb_right)
            node=node->rb_right;
        return node;
    }
    /* No left-hand children. Go up till we find an ancestor which
       is a right-hand child of its parent */
    while ((parent = rb_parent(node)) && node == parent->rb_left)
        node = parent;
    return parent;
}
void rb_replace_node(struct rb_node *victim, struct rb_node *new_node, struct rb_root *root)
{
    struct rb_node *parent = rb_parent(victim);
    /* Set the surrounding nodes to point to the replacement */
    if (parent) {
        if (victim == parent->rb_left)
            parent->rb_left = new_node;
        else
            parent->rb_right = new_node;
    } else {
        root->rb_node = new_node;
    }
    if (victim->rb_left)
        rb_set_parent(victim->rb_left, new_node);
    if (victim->rb_right)
        rb_set_parent(victim->rb_right, new_node);
    /* Copy the pointers/colour from the victim to the replacement */
    *new_node = *victim;
}
struct rb_node *rb_search(struct rb_root *root, struct rb_key key)
{
    struct rb_node *p = root->rb_node;
    while(p != NULL && rb_compare(p->rb_key, key) != 0) {
        p = (rb_compare(p->rb_key, key) > 0) ? p->rb_left : p->rb_right;
    }
    return p;
}
void rb_traverse(struct rb_node *p)
{
    if (p) {
        if (p->rb_left)
            rb_traverse(p->rb_left);
        printf(" %d ", p->rb_key.key);
        if (p->rb_right)
            rb_traverse(p->rb_right);
    }
}